As summer starts to assert its grip on the garden, roses are starting to bloom and fill our gardens with colour and perfume. Now I know that a lot of people think that roses are either too much work or just annoying, prickly shrubs. I am happy to admit that, even as a confessed rose fanatic, I find spring pruning something of a chore and, having planted a mixed hedge that includes roses, around my garden, mowing can sometimes be a painful experience. But roses have so many other good qualities that they are a must in every garden. I could not imagine a garden without roses and they were among the first plants I added to my own garden.
Single-flowered roses, including the tough and easy ‘rugosa’ roses are fragrant and are loved by bees. They are among the most prickly though!
Roses really have quite simple needs and even pruning is not complicated.
At this time of year the main things to consider are feeding and disease control and, in a few weeks, deadheading.
Feeding
Roses require regular feeding. This will ensure plenty of flowers and healthy growth but also help the roses resist disease. In addition to the main plant nutrients (nitrogen, phosphorus and potassium) they require ‘trace elements’ including magnesium. For this reason it is best to use a rose fertiliser or an organic rose fertiliser and not just growmore. You should apply the rose fertiliser in spring and again after you deadhead the first flush of flowers, in July.
It is always beneficial to much around the roses in spring but do not rely on this to supply all the necessary nutrients. Mulching will also cover any blackspot spores on the soil and can help to reduce disease.
If growing roses in pots on the patio, always use a loam-based compost and not multipurpose compost, and feed every week with a balanced liquid fertiliser.
Disease
Not all roses are prone to disease and many modern kinds are very resistant. All roses are more prone to disease if they are growing weakly, so make sure you feed them and avoid bark mulch around them which deprives the roses of nutrients as it decomposes.
The most serious disease is black spot. This fungal disease is more common in wet weather and, after the black spots appear, the leaf turns yellow and drop off. This weakens the plant.
Roses also suffer from mildew, but usually at the end of summer. The powdery coating covers the new leaves and sometimes the buds. Dryness at the roots and the heavy dews of autumn encourage it.
Rust is also sometimes an issue but the ways to control mildew and black spot should help prevent this.
The important thing about fungal diseases is that you cannot spray to ‘cure’ them, only to help prevent disease. So if you have had the disease on your roses before, you are likely to see the problem again. If you only have a few roses then buy a ready-to-use rose fungicide and spray the leaves every two or three weeks, according to instructions, to keep the leaves free of disease, before disease strikes. If you prefer you can use a combined fungicide and insecticide to kill aphids but there is really no need to because ladybirds and other predators usually ‘mop them up’. I never spray against aphids on my roses.
Deadheading
The main season for pruning is in spring but don’t let your secateurs gather dust in summer. When the flowers or clusters of flowers fade on your reblooming roses (those that will bloom all summer) they need to be removed. This will keep the plants tidy, it encourages more flowers to grow and it prevents rose hips from forming which in most cases, though not all, is undesirable.
When all the flowers in a cluster have faded, prune back the shoot to the uppermost ‘large’ leaf. In general, if you cut back only lightly – not removing much stem – the re-bloom will be quicker than if you cut back harder. But these new flowers will have shorter stems.
Without wishing to complicate the matter, if you have either old-fashioned, once-blooming roses or rambler roses (NOT climbing roses) that only bloom once, such as ‘Albertine’, these are pruned now – removing the long, flowered stems to make room for new shoots that will bloom next year.
A little time spent among your roses throughout summer will keep them healthy and blooming, but what a lovely thing to do, admiring and sniffing your beautiful roses. Just remember the strong gloves.
